Tubulin is the major constituent of microtubules, a cylinder consisting of laterally associated linear protofilaments composed of alpha- and beta-tubulin heterodimers (PubMed:23001566, PubMed:26732629, PubMed:28013290). Microtubules grow by the addition of GTP-tubulin dimers to the microtubule end, where a stabilizing cap forms. Below the cap, tubulin dimers are in GDP-bound state, owing to GTPase activity of alpha-tubulin. Plays a critical role in proper axon guidance in both central and peripheral axon tracts (PubMed:23001566). Implicated in neuronal migration (PubMed:19465910).
